


momentary relapse

by Sniggy (Sniggyfrumps)



Category: Gravity Falls
Genre: Aged-Up Character(s), Choking, M/M, PWP, Sexual Content, Xeno
Language: English
Status: Completed
Published: 2015-08-17
Updated: 2015-08-17
Packaged: 2018-04-15 06:29:08
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,353
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4596411
Author URL: https://archiveofourown.org/users/Sniggyfrumps/pseuds/Sniggy
Summary: <blockquote class="userstuff">
              <p>"Y-your dick isn't--ah--the damn Kryptos," Dipper interjects, barely keeping his voice from hitching.</p>
            </blockquote>





	momentary relapse

**Author's Note:**

> this is not human!bill, but written with objecthead!bill in mind, as seen on my tumblr. also pretty much pwp.

Dipper's fingers aren't the small and chubby stumps of a twelve-year old anymore, but even with ten years to grow they still can't fully wrap around the broad, thin shoulders of the figure above him.

He digs fingers into the cloth of the golden three-piece suit; uneven nails sticking to the material Dipper's sure is somehow made up of children's nightmares and radioactive waste, considering how merely thouching it makes his hairs electrify and stand on edge all the way up his arms to his shoulders.

"Watch the goods, kid," Cipher huffs into Dipper's ear, never much for wandering hands splitting hairs and threads.The Pines twin doesn't answer, mostly given that Cipher's got one lean fist on Dipper's adam's apple and spindly fingers wrapped around his throat like seperate Coluber constrictors. "This jacket's probably worth more than whatever organs sloshing inside of you could fetch your uncle on the ol' black market," he sniggers.

Of course Grunkle Stan wouldn't--not in _this_ timeline, no, but Bill Cipher likes to tell Dipper of all the _other_ Stans, and all the _other_ Dippers and all the _other_ ways his life didn't culminate in this moment, with Dipper sweating and panting on his back and a dream demon pushing into him in a steady, far too patient rhythm.

Cipher's thumb slides under Dipper's chin and pushes the young man's head backwards, straining the tendons in the neck, forcing Dipper's eyes away from Bill's own, all-seeing one.

A quiet grunt turning into a groan slips out of Dipper's mouth. It reverberates through his throat, and he's certain the demon can feel it, certain those dark fingers are aware of every shiver and shudder.

Dipper's hands flatten out against Cipher's shoulders, pressing down on whatever body lies under the immaculate suit--he's never seen it, although, if the hands are anything to go by, the skin is dark and dry and polished--like a blacksnake's--but perfectly smooth and without purchase--like a metal object, something inorganic and altogether alien. He's tried to peel off the golden jacket or slip fingers under the cream shirt that peeks out behind the bowtie, but Bill warns him off with either an offhand joke about alien geometry, a _look_ or blue fire licking off a couple of brown hairs and fingertips, depending on how irritable the demon feels in _that_ particular moment.

Dipper knows that he should probably not think to look down to see what's pushing into him, stretching him open and making his legs shiver and spread open every time Cipher's clothed groin against his own. Not that Bill's strict hand around his neck is going to let him. He's pretty sure it _isn't_ a human cock though, and he's _definitely_ sure he's not willing to confirm.

It feels _so good_ though, and the morbid curiosity still brings him back to this moment, to his knees digging into Bill Cipher's sides and his fingers wandering despite the demon's _many_ warnings.

Dipper Pines never could leave well enough alone.

"One day I'll find out what's under your coat," he groans at the tail-end of a particularly nice jut of Cipher's hips (what probably counts for hips under those trousers).

"The secrets of the universe," Cipher smartly replies, and casually grabs a bruising hold around Dipper's shoulder as the older (much, much, _much_ ) older being repositions him(it)self over Dipper.

"The-hhh-s-secret of the universe is in your pants?" Dipper questions, barely managing a raised brow as Cipher sets a much quicker pace.

"Where else would I keep it, huh? Or maybe it's in my _other_ set of pants, along with the key to the Voynich Manuscript and the reason humans have uvulas," Cipher grins as much as a being without a mouth can. Dipper wants to squint and grimace sceptically but finds he can barely keep eye contact with the demon as he shudders across the bed sheets.

"F-fuck, _Bill--"_

Dipper isn't sure how Bill's body (or approximation of one) even works or how the being is able to fuck him into the mattress despite not having to remove his clothes to do so. He's come to the conclusion he understands Bill's semi-anthropomorphic form even less than the tiny floating triangle form he seems so fond of when _'making business calls'._ The floating triangle part is still there, instead it seems to hover at approximately neck-length above a nice (hands off, kid) yellow suit covering what to D

ipper feels like a hard, lean body, but what looks like staring into the void might feel like. The twin finds he can barely focus on any part of Bill's black, smooth skin for longer than ten seconds before his vision goes blurry and what feels like his retina trying to escape into the back of his skull ensues.

Bill feels slick and hot inside him, like a lubed-up, warmblooded human cock; but he also feels...  _off_ somehow, as if Dipper's body is trying to reject a reality it isn't compatible with despite having it very _literally_ thrust upon him over and over.

"I know that look on your face, kid," Cipher says, eye crinkling in what is probably his version of a lop-sided smirk. "Trying to suss me out like you've got any real chance at breaking this code."

"Y-your dick isn't--ah--the damn Kryptos," Dipper interjects, always keen to be contrary, but barely keeping his voice from hitching.

"Shows what you know, Pinetree!" Bill sing-songs, too damn pleased with himself and too composed while Dipper is coming undone at the end of his non-Euclidian cock.

Cipher's hand tighten around his throat, Dipper can feel his windpipe constrict and his mouth go dry. The demon presses him into the sheets by his neck, and Dipper curls around the demon, hands scrabbling for hold over the smooth, perfect cloth of that goddamn suit.

"B-bill--" he coughs, mind growing fuzzy even as the demon plows into him, hard rough motions that make Dipper's knees go weak around the other's thin waist. Or it might be the lack of air.

The demon arches over him, and pushes his weird not-face close to Dipper's flushed ear, whispering to him with a voice that seems to come from the blinking triangle and from inside Dipper's own head all at once.

"Feeling light-headed?"

_"B-b--"_

"Not letting you go before you come all your stomach. Gonna see you make a _sticky mess_ of yourself before you get to draw in another breath. _Sucks_ , hah!" he cackles, like the nasally, criminally unfunny jerk he is.

 _"Hnn--"_ Dipper groans, eyes shuddering closed.

"Don't quit, you're _so_ close!" Bill heckles, and his other hand relinguishes Dipper's shoulder, and the next thing Dipper knows is that those clever fingers are around his own very human cock, pumping and working him in ways the demon has _no business_ being so good at, for the little he seems to grasp about human bodies.

His head is rushing with adrenaline and what little blood that's left to circulate his body is running to his dick as Bill's clever fucking fingers stroke up and down the shaft. Dipper's hands fists in Cipher's suit, bunching up the jacket as he comes in a hard spurt, on the verge of passing out.

He must have gone unconscious after all, or maybe he just closed his eyes for a split second, because when Dipper opens them next, he's drenched in sweat and his own come, but Cipher's gone. Only clue that anyone else might have ever been in Dipper's cluttered room is the blue bruises blooming on his shoulder and around his neck, but even then Dipper can't say he didn't do that by himself in a particularly feverish haze of hormones.

Panting, and looking to the ceiling as blood and endorphines rush his head, there's just the ghosts of Bill's fingers and the slight tingling sensation in his own fingertips from where Dipper no doubt rumpled Bill's previously snappy-looking suit.

Next time, he thinks. Next time he's going to either going to _keep_ his own goddamn pants on, or get that asshole triangle's off. Next time.


End file.
